The present invention relates to a sorting device for sorting out and classifying differently sized thin pieces such as tickets, metal pieces, coins, or other tokens according to their size.
Small articles of different sizes can manually be sorted out according to their size, but the manual sorting operation has been time-consuming and subjected to errors. Various automatic sorting mechanisms have heretofore been used for mechanically or electrically classifying and sorting out different kinds of pieces according to their size. Though the known automatic sorters are highly effective to sort out relatively heavy and thick objects such as coins or nuts, the mechanisms fail to divide relatively light and thin pieces into groups according to their size. No sorting device has been devoloped which is capable of sorting out light and thin articles without suffering from errors. It has therefore been customary practice to resort to manual procedures for sorting out pieces of paper such as tickets, pieces of cloth, or thin pieces of metal.
There has been proposed a sorting device (as disclosed in U. S. Pat. Application Ser. No. 470,720, now U.S. Pat. No. 4,535,895) comprising a rotatable sorter drum in the form of a hollow cylinder having a plurality of openings defined in the cylindrial wall thereof for discharging pieces of particular size only through the openings out of the sorter drum. The sorter drum has sorter mechanisms including tapered tonques sheared off the cylindrical wall radially outwardly thereof and guide strips extending along side edges of the tapered tongues, the openings being defined in the shape of rectangles by the tapered tongues and the guide strips, which jointly form discharge chutes leading to the openings. In operation, the sorter drum is rotated about its own axis to guide pieces in the sorter drum onto the chutes along the guide strips, and only those pieces smaller than the shape of the openings are allowed to pass through the openings out of the sorter drum. The prior sorting device has however been disadvantageous in that it is tedious and time-consuming to attach the guide strips securely in place along the side edges of the tapered tongues. It has been difficult to define openings of uniform shape, and hence to assemble uniformly designed sorting mechanisms. The assembling operation has mainly been carried out manually with utmost care over a long period of time.
In the proposed sorting device, the sorter drum is rotated by a motor, which will have to be manually turned off when all of pieces to be sorted out are discharged from the sorter drum. The sorting device has to be supervised by an operator who will stop or reverse the motor when all pieces are discharged to prevent unwanted power consumption or wear on moving parts. However, the cost of labor is high and the efficiency of operation of the sorter varies from operator to operator. There has been a growing demand for an automatic sorting device to achieve a more efficient sorting operation.